Acoustic wave elements, antenna duplexers, modules and electronic devices using the same

ABSTRACT

An acoustic wave element ( 100 ) according to certain examples includes a piezoelectric body ( 130 ), an interdigital transducer (IDT) electrode ( 140, 150 ) disposed above the piezoelectric body ( 130 ), and a connection electrode ( 160 ) disposed above the piezoelectric body ( 130 ) and connected to the IDT electrode ( 140, 150 ). A first insulation layer ( 172 ) covers the connection electrode ( 160 ), and a second insulation layer ( 174   a,    174   b ) covers the IDT electrode ( 140, 150 ). The first insulation layer ( 172 ) disposed above the connection electrode ( 160 ) has a first thickness T in a direction perpendicular to an upper surface of the piezoelectric body ( 130 ) and the second insulation layer ( 174   b ) disposed above the IDT electrode ( 150 ) has a second thickness K in the direction perpendicular to the upper surface of the piezoelectric body ( 130 ). The first thickness T is less than the second thickness K based on  FIG. 2C  and the relevant description.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. §119 andPCT Article 8 to co-pending JP Patent Application No. 2014-152547 filedon Jul. 28, 2014, which is incorporated herein by reference in itsentirety for all purposes.

TECHNICAL FIELD

Aspects and embodiments relate generally to an acoustic wave element, anantenna duplexer using the same, and an electronic device using theantenna duplexer.

BACKGROUND ART

A conventional antenna duplexer generally includes a transmission filterand a reception filter. The transmission filter may include a firstinterdigital transducer (IDT) electrode configured as a transmissionresonator on a piezoelectric body. The reception filter may include asecond IDT electrode configured as a reception resonator on thepiezoelectric body. Each IDT electrode is covered with an insulationlayer. U.S. Patent Application Publication No. 2012/0019102 discloses anexample of such a conventional antenna duplexer.

CITATION LIST Patent Literature

PTL 1: U.S. Patent Application Publication No. 2012/0019102

SUMMARY OF INVENTION

Conventional acoustic wave elements such as may be used in theabove-mentioned antenna duplexer may require a longer lead time in amanufacturing process and there is a need for the manufacturing processto be simplified.

To address this issue, aspects and embodiments are directed to animproved acoustic wave element and manufacturing process thereof.According to one embodiment, an acoustic wave element comprises apiezoelectric body, an interdigital transducer (IDT) electrode disposedabove the piezoelectric body, a connection electrode disposed above thepiezoelectric body and connected to the IDT electrode, a firstinsulation layer covering the connection electrode, and a secondinsulation layer covering the IDT electrode. The first insulation layeris disposed above the connection electrode and has a first thickness Tin a direction perpendicular to an upper surface of the piezoelectricbody, and the second insulation layer is disposed above the IDTelectrode and has a second thickness K in the direction perpendicular tothe upper surface of the piezoelectric body, the first thickness T beingless than the second thickness K. According to the aforementionedconfiguration, the example of the acoustic wave element may allow themanufacturing process to be simplified, and a highly-reliable acousticwave element may be achieved. In particular, as discussed in more detailbelow, the relationship between the thickness of the insulation layer onthe upper surface of the IDT electrode and that of the connectionelectrode may allow the manufacturing process of the acoustic waveelement to be greatly simplified.

According to one embodiment, an acoustic wave element comprises apiezoelectric body, an interdigital transducer (IDT) electrode disposedabove the piezoelectric body, a connection electrode disposed above thepiezoelectric body and connected to the IDT electrode, a firstinsulation layer covering the connection electrode and having a firstthickness T above the connection electrode in a direction perpendicularto an upper surface of the piezoelectric body, and a second insulationlayer covering the IDT electrode and including a first portion having asecond thickness K above the IDT electrode in the directionperpendicular to the upper surface of the piezoelectric body, the secondthickness K being greater than the first thickness T.

Various embodiments of the acoustic wave element may include any one ormore of the following features.

In one example of the acoustic wave element, the IDT electrode includesa first IDT electrode forming a first filter and a second IDT electrodeforming a second filter, the first portion of the second insulationlayer being disposed above the second IDT electrode, and the secondinsulation layer further including a second portion disposed above thefirst IDT electrode and having a third thickness S in the directionperpendicular to the upper surface of the piezoelectric body, the thirdthickness S being different from the second thickness K. In one examplein which the acoustic wave element is an antenna duplexer, the firstfilter is configured as a reception filter of the antenna duplexer topass a first signal in a first frequency band, and the second filter isconfigured as a transmission filter of the antenna duplexer to pass asecond signal in a second frequency band different from the firstfrequency band.

In one example, the third thickness S is approximately equal to thefirst thickness T.

In another example, the first insulation layer and the second insulationlayer are made of a same material. In one example the material of thefirst and second insulation layers is oxidized silicon. In anotherexample the material of the first and second insulation layers issilicon nitride.

In one example the IDT electrode includes first and second layersarranged in the direction perpendicular to the upper surface of thepiezoelectric body, the first layer being made of a material differentfrom that of the second layer. The materials of the first and secondlayers of the IDT electrode can be selected from a group consisting ofaluminum, copper, gold, titanium, tungsten, molybdenum, platinum,chromium, and an alloy composed mainly of one or more of these metals,for example. In another example, the IDT electrode is made of a singlemetal element selected from a group consisting of aluminum, copper,gold, titanium, tungsten, molybdenum, platinum, and chromium.

The acoustic wave element may further comprise an extraction electrodeconnected to the connection electrode and disposed above the connectionelectrode, and an external terminal electrode connected to theextraction electrode and disposed above the extraction electrode.

The acoustic wave element may further comprise a wiring electrodedisposed above the first insulation layer and insulated from theconnection electrode by the first insulation layer. In one example thefirst insulation layer includes a first portion disposed above theconnection electrode and having the first thickness T, and a secondportion disposed between the connection electrode and the wiringelectrode and having a fourth thickness W in the direction perpendicularto the upper surface of the piezoelectric body, the fourth thickness Wbeing less than the second thickness K.

According to another embodiment, an electronic device comprises anexample of the above-described acoustic wave element, a semiconductorelement connected to the acoustic wave element, and a reproductiondevice connected to the semiconductor element.

Another embodiment is directed to a module including an example of theabove-described acoustic wave element.

Further embodiments are directed to communications device including anexample of the acoustic wave element or the module.

According to another embodiment, an antenna duplexer comprises apiezoelectric body, a first filter including a first interdigitaltransducer (IDT) electrode disposed above the piezoelectric body, asecond filter including a second IDT electrode disposed above thepiezoelectric body, and a connection electrode disposed above thepiezoelectric body and connected to the first and second IDT electrodes.A first insulation layer is disposed over the connection electrode andhas a first thickness T above the connection electrode in a directionperpendicular to an upper surface of the piezoelectric body. The antennaduplexer further includes a second insulation layer including a firstportion disposed over the first IDT electrode and having a secondthickness S above the first IDT electrode in the direction perpendicularto the upper surface of the piezoelectric body, and a second portiondisposed over the second IDT electrode and having a third thickness Kabove the second IDT electrode in the direction perpendicular to theupper surface of the piezoelectric body. The second thickness S isapproximately equal to the first thickness T, and the third thickness Kis greater than the first thickness T.

In one example in which the first filter is a reception filter and thesecond filter is a transmission filter, the first IDT electrode includesa first series resonator connected to an antenna terminal by theconnection electrode, a second series resonator connected to the firstseries resonator in series by the connection electrode and connected toan output terminal, and a first parallel resonator connected to thefirst series resonator by the connection electrode. The second IDTelectrode may include a third series resonator connected to the antennaterminal by the connection electrode, a fourth series resonatorconnected to the third series resonator in series by the connectionelectrode in series and connected to an input terminal, and a secondparallel resonator connected to the third series resonator by theconnection electrode.

Still other aspects, embodiments, and advantages of these exemplaryaspects and embodiments are discussed in detail below. Embodimentsdisclosed herein may be combined with other embodiments in any mannerconsistent with at least one of the principles disclosed herein, andreferences to “an embodiment,” “some embodiments,” “an alternateembodiment,” “various embodiments,” “one embodiment” or the like are notnecessarily mutually exclusive and are intended to indicate that aparticular feature, structure, or characteristic described may beincluded in at least one embodiment. The appearances of such termsherein are not necessarily all referring to the same embodiment.

BRIEF DESCRIPTION OF DRAWINGS

Various aspects of at least one embodiment are discussed below withreference to the accompanying figures, which are not intended to bedrawn to scale. The figures are included to provide illustration and afurther understanding of the various aspects and embodiments, and areincorporated in and constitute a part of this specification, but are notintended as a definition of the limits of the invention. In the figures,each identical or nearly identical component that is illustrated invarious figures is represented by a like numeral. For purposes ofclarity, not every component may be labeled in every figure. In thefigures:

FIG. 1 is a plan view showing an example of an acoustic wave elementaccording to the present invention;

FIG. 2A is a cross-sectional view of the example of the acoustic waveelement of FIG. 1 taken along line A-AA in FIG. 1;

FIG. 2B is a cross-sectional view of the example of the acoustic waveelement of FIG. 1 taken along line B-BB in FIG. 1;

FIG. 2C is a cross-sectional view of the example of the acoustic waveelement of FIG. 1 taken along line C-CC in FIG. 1;

FIG. 3A is a plan view showing another example of an acoustic waveelement according to aspects of the present invention;

FIG. 3B is a cross-sectional view of the example of the acoustic waveelement of FIG. 3A taken along line D-DD in FIG. 3A;

FIG. 4 is a process flow diagram showing one example of a manufacturingprocess for an example of an acoustic wave element according to aspectsof the present invention;

FIG. 5A is a process flow diagram illustrating in cross-sectionstructural aspects corresponding to the manufacturing process of FIG. 4for an example of the acoustic wave element of FIG. 1 taken along lineA-AA in FIG. 1;

FIG. 5B is a process flow diagram illustrating in cross-sectionstructural aspects corresponding to the manufacturing process of FIG. 4for the example of the acoustic wave element of FIG. 1 taken along lineB-BB in FIG. 1;

FIG. 5C is a process flow diagram illustrating in cross-sectionstructural aspects corresponding to the manufacturing process of FIG. 4for the example of the acoustic wave element of FIG. 1 taken along lineC-CC in FIG. 1;

FIG. 6 is a block diagram schematically showing an example of anelectronic device using an example of an acoustic wave element accordingto aspects of the present invention;

FIG. 7 is a block diagram schematically showing an example of a moduleusing an example of an acoustic wave element according to aspects of thepresent invention; and

FIG. 8 is a block diagram schematically showing an example of acommunication device using an example of an acoustic wave elementaccording to aspects of the present invention.

DESCRIPTION OF EMBODIMENTS

As discussed above, aspects and embodiments are directed to an acousticwave element, and manufacturing process thereof, the acoustic waveelement having a structure that allows the manufacturing process to begreatly simplified relative to conventional processes.

It is to be appreciated that embodiments of the methods and apparatusesdiscussed herein are not limited in application to the details ofconstruction and the arrangement of components set forth in thefollowing description or illustrated in the accompanying drawings. Themethods and apparatuses are capable of implementation in otherembodiments and of being practiced or of being carried out in variousways. Examples of specific implementations are provided herein forillustrative purposes only and are not intended to be limiting. Also,the phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use herein of“including,” “comprising,” “having,” “containing,” “involving,” andvariations thereof is meant to encompass the items listed thereafter andequivalents thereof as well as additional items. References to “or” maybe construed as inclusive so that any terms described using “or” mayindicate any of a single, more than one, and all of the described terms.Any references to front and back, left and right, top and bottom, upperand lower, and the like are intended for convenience of description, notto limit the present systems and methods or their components to any onepositional or spatial orientation. In particular, as described belowterms indicating directions such as “above,” “below,” “upper surface,”“lower surface” and the like are used for designating relativedirections depending only on a relative positional relationship betweencomponents included in embodiments of the acoustic wave element, such asa substrate, an IDT electrode and the like, and therefore are notintended to designate absolute directions such as a vertical directionfor example.

FIG. 1 is a plan view showing an example of an acoustic wave elementaccording to certain embodiments. In the example of FIG. 1, the acousticwave element is exemplified as an antenna duplexer 100 suitable for CDMAstandard Band 8. The antenna duplexer 100 includes a first filter 110and a second filter 120. The first filter 110 may be a reception filterto allow signals in a first frequency band, for example, ranging from925 MHz to 960 MHz for CDMA standard Band 8, to pass as receptionsignals. The second filter 120 may be a transmission filter to allowsignals in a second frequency band lower than the reception frequencyband, for example, ranging from 880 MHz to 915 MHz for CDMA standardBand 8, to pass as transmission signals.

The acoustic wave element includes a piezoelectric body 130, and a firstinterdigital transducer (IDT) electrode 140 and a second IDT 150disposed on an upper surface 135 of the piezoelectric body 130. Theacoustic wave element further includes a connection electrode 160disposed on the upper surface 135 and electrically connecting the firstIDT electrode 140 to the second IDT electrode 150, and insulation 170(shown in FIGS. 2A-2C and 5A-5C and discussed further below) coveringthe upper surface 135, the first IDT electrode 140, the second IDTelectrode 150, and the connection electrode 160.

The first IDT electrode 140 may include comb-shaped electrodes 141 and142 arranged opposed to each other. The comb-shaped electrode 141 mayinclude a bus bar 143 and a plurality of electrode fingers 144 extendingfrom the bus bar 143 in parallel. The comb-shaped electrode 142similarly may include a bus bar 145 and a plurality of electrode fingers146 extending from the bus bar 145 in parallel and overlapped with theelectrode fingers 144.

The second IDT electrode 150 may include comb-shaped electrodes 151 and152 arranged opposite to each other. The comb-shaped electrode 151 mayinclude a bus bar 153 and a plurality of electrode fingers 154 extendingfrom the bus bar 153 in parallel. The comb-shaped electrode 152 mayinclude a bus bar 155 and a plurality of electrode fingers 156 extendingfrom the bus bar 155 in parallel and overlapped with the electrodefingers 154.

The first filter 110 as a reception filter may include a first seriesresonator 210 connected to an antenna terminal 182 via the connectionelectrode 160, a second series resonator 212 connected to the seriesresonator 210 via the connection electrode 160 in series, an outputterminal 184 connected to the second series resonator 212, and aparallel resonator 214 connected to the first series resonator 210 viathe connection electrode 160.

The second filter 120 as a transmission filter may include a firstseries resonator 220 connected to the antenna terminal 182 via theconnection electrode 160, a second series resonator 222 connected to theseries resonator 220 via the connection electrode 160 in series, aninput terminal 186 connected to the second series resonator 222, and aparallel resonator 224 connected to the first series resonator 220 viathe connection electrode 160.

Each of the antenna terminal 182, the output terminal 184, and the inputterminal 186 may function as an external terminal electrode 180 forconnections to external circuitry.

In one example the piezoelectric body 130 includes a material made, forexample, based on lithium niobate, lithium tantalate, potassium niobate,quartz, and the like.

Examples of the first IDT electrode 140, the second IDT electrode 150,and the insulation layer 170 according to certain embodiments aredescribed with reference to FIGS. 2A-2C and 5A-5C. FIG. 2A is across-sectional view of the example of the acoustic wave elementexemplified as antenna duplexer 100 taken along line A-AA in FIG. 1.FIG. 2B shows a cross-sectional view of the first filter 110 taken alongline B-BB in FIG. 1. FIG. 2C shows a cross-sectional view of the secondfilter 120 taken along line C-CC in FIG. 1.

Each of the first IDT electrode 140 and the second IDT electrode 150 maybe made, for example, of a single metal element, such as, aluminum,copper, gold, titanium, tungsten, molybdenum, platinum or chromium, analloy composed mainly of one or more of these metal elements, or amulti-layered structure thereof. The multi-layered structure may beexemplified as a layered structure in which a first layer and a secondlayer (not shown) are layered in the direction perpendicular to theupper surface 135 of the piezoelectric body 130 in the first IDTelectrode 140 and the second IDT electrode 150. Furthermore, thematerial of the first layer may be different from that of the secondlayer.

The insulation 170 may be made of an oxide material having an increasedinsulation performance, such as a medium mainly composed of oxidizedsilicon, for example. The insulation 170 may have a layered structure.The layered structure of the insulation 170 is not limited to anyspecific structure, and a multi-layered structure with a differentmaterial such as silicon nitride may be implemented.

The connection electrode 160 may be electrically connected to theexternal terminal electrode 180 via an extraction electrode 190. Thematerial of the extraction electrode 190 is not limited to a specificmaterial; however, in the interest of simplifying the manufacturingprocess of the acoustic wave element, the material may preferably be asame material as that used for the first IDT electrode 140, the secondIDT electrode 150, and the connection electrode 160. Similar to theextraction electrode 190, the material of the external terminalelectrode 180 is not limited to a specific material; however, in theinterest of simplifying the manufacturing process of the acoustic waveelement, the material may preferably be a same material as that used forthe first IDT electrode 140, the second IDT electrode 150, and theconnection electrode 160.

It is to be appreciated that, although described above and illustratedas separate, in other embodiments the connection electrode 160, theextraction electrode 190, and the external terminal electrode 180 mayhave a monolithic structure formed with a same material.

Furthermore, when the connection electrode 160 is formed simultaneouslyand integrally with the first IDT electrode 140 and the second IDTelectrode 150 in a thin film deposition process, the first IDT electrode140 and the second IDT electrode 150 may preferably be made of a samematerial in order to simplify the manufacturing process. Stillfurthermore, the extraction electrode 190 and the external terminalelectrode 180 may preferably be made of a same material and in a sameconfiguration as those of the connection electrode 160, the first IDTelectrode 140, and the second IDT electrode 150 similar to the above inorder to simplify the manufacturing process.

Referring now to FIGS. 2A-2C, the insulation 170 used in embodiments ofthe acoustic wave element is described in terms of the thicknessesthereof. An insulation layer disposed on the upper surface of theconnection electrode 160 is designated as a first insulation layer 172and a thickness thereof is designated as T. An insulation layer disposedon the upper surface of the first IDT electrode 140 and the second IDTelectrode 150 is designated as a second insulation layer 174, and athickness of a first portion 174 a thereof on the first IDT electrode140 is designated as S, whereas a thickness of a second portion 174 bthereof on the second IDT electrode 150 is designated as K. According toone embodiment, the thickness T of the first insulation layer 172 on theconnection electrode 160 is less than the thickness K of the secondportion of the second insulation layer 174 on the second IDT electrode150. With this configuration, the time required for etching the firstinsulation layer 172 to form the extraction electrode 190 may be reducedsuch that the manufacturing process of the acoustic wave element may besimplified. Furthermore, the thickness S of the first portion of thesecond insulation layer 174 on the upper surface of the first IDTelectrode 140 may preferably be made approximately equal to thethickness T of the first insulation layer 172 in order to furthersimplify the manufacturing process.

In the example illustrated in FIG. 1, the first IDT electrode 140 ispart of the first (reception) filter 110, and the second IDT electrode150 is part of the second (transmission) filter 120; however, it is tobe appreciated that the thickness magnitude relationship between theinsulation layers 172, 174 a, and 174 b on the respective upper surfacesis not limited based on the designation of the reception filter or thetransmission filter.

FIGS. 3A and 3B illustrate another embodiment of an acoustic waveelement according to certain aspects. In particular, FIGS. 3A and 3Bshow an acoustic wave element exemplified as an example of a DMS(Double-Mode-SAW) filter 300. The DMS filter 300 can replace either orboth of the first filter 110 and/or the second filter 120 in the antennaduplexer 100 of FIG. 1. FIG. 3A is a plan view of the DMS filter 300,and FIG. 3B is a cross-sectional view taken along line D-DD in FIG. 3A.

Referring to FIG. 3A, the DMS filter 300 includes a central IDTelectrode 310 formed by a pair of comb-shaped electrodes 312, and twoside IDT electrodes 320 each disposed in a propagation direction of anacoustic wave and formed by a pair of comb-shaped electrodes 322. Incertain examples, the DMS filter 300 further includes reflectors 360disposed on opposite sides of the two side IDT electrodes 320.

According to one embodiment, one of the comb-shaped electrodes 312forming the central IDT electrode 310 is be connected to a GND electrode330 facing an output terminal 186 via the connection electrode 160,whereas the other of the comb-shaped electrodes 312 is be connected toan antenna terminal 182 via the connection electrode 160. Two of thecomb-shaped electrodes 322 forming the two side IDT electrodes 320 andarranged facing the antenna terminal 182 may be electrically connectedto each other via the connection electrode 160, and the other twocomb-shaped electrodes 322 arranged facing the output terminal 186opposed to the antenna terminal 182 may also be electrically connectedto each other via the connection electrode 160.

In one example, the two comb-shaped electrodes 322 of the two side IDTelectrodes 320 facing the antenna terminal 182 can have an electricpotential different from that of the comb-shaped electrodes 312 of thecentral IDT electrode 310 facing the antenna terminal 182 and may not beelectrically connected to the comb-shaped electrodes 312. For example,the electrodes having different electrical potentials may be wired in athree-dimensionally crossing manner interposing an insulator between theelectrodes in order to avoid a complex two-dimensional circuit wiringstructure.

For purposes of description, an insulation layer disposed on an uppersurface of the central IDT electrode 310 and the two side IDT electrodes320 is designated as a third insulation layer 340. The third insulationlayer 340 is not shown in FIG. 3A for clarity of the drawing. Nocross-sectional views of the central IDT electrode 310 and the two sideIDT electrodes 320 in the DMS filter 300 are shown in the drawingsbecause the cross-sectional views correspond to those of the first IDTelectrode 140 and the second IDT electrode 150, respectively, of thefirst filter 110 and the second filter 120 as shown in FIGS. 2B and 2C.

Referring to FIG. 3B, the DMS filter 300 can include a wiring electrode350 routed above the connection electrode 160 via the third insulationlayer 340. In one example, a first portion 342 of the third insulationlayer 340 disposed between the connection electrode 160 and the wiringelectrode 350 has a thickness W in a direction perpendicular to theupper surface 135 of the piezoelectric body 130. The thickness W maypreferably be less than a thickness of a second portion the thirdinsulation layer 340 disposed above the central IDT electrode 310 or thetwo side IDT electrodes 320 in the direction perpendicular to the uppersurface of the piezoelectric body 130.

In the case where the wiring electrode 350 is formed by a vapordeposition process, the third insulation layer 340 may be formed sothick that the coverage of the wiring electrode 350 may be degraded andfurthermore it can be possible that the wiring electrode 350 has such alocally thinned portion that the electrode may have a greater thandesirable resistance. Accordingly, to avoid such problems, the thicknessW of the first portion of the insulation layer 340 may preferably bemade as thin as possible provided that an insulating effect can bemaintained between the connection electrode 160 and the wiring electrode350. In this case, the resistivity can be sufficiently low for theelectrodes to operate properly.

Referring to FIG. 4, there is illustrated a flow diagram for one exampleof a manufacturing process, or relevant portion thereof, for an exampleof an acoustic wave element according to certain embodiments. FIG. 5Ashows the resulting structure in cross-sectional view, corresponding toFIG. 2A, taken long line A-AA in FIG. 1. FIG. 5B shows the resultingstructure in cross-sectional view, corresponding to FIG. 2B, taken longline B-BB in FIG. 1. FIG. 5C shows the resulting structure incross-sectional view, corresponding to FIG. 2C, taken long line C-CC inFIG. 1.

As shown in FIGS. 4 and 5A-5C, the first IDT electrode 140, the secondIDT electrode 150, and the connection electrode 160 of desired shapescan be simultaneously and integrally formed on the upper surface of thepiezoelectric body 130 using masks in an electrode forming step 410.

In step 420, the insulation 170 is formed on the upper surfaces of eachelectrode and the piezoelectric body 130. Step 420 can be a filmdeposition step.

Next, the insulation 170 may be processed in an etching step 430. Instep 430, the first portion of the second insulation layer 174 a on theupper surface of the first IDT electrode 10 may be etched more than thesecond portion of the second insulation layer 174 b on the upper surfaceof the second IDT electrode 150, such that the first portion of thesecond insulation layer 174 a on the upper surface of the first IDTelectrode 140 may be formed thinner than the second portion of thesecond insulation layer 174 b on the upper surface of the second IDTelectrode 150, as may be seen with reference to FIGS. 5B and 5C. Thisrelative thickness configuration may improve an electromechanicalcoupling coefficient of the acoustic wave element. In certainembodiments, in step 420 the thickness of the insulation 170 can be madeto be the desired thickness of the second portion of the secondinsulation layer 174 b so that the etching step 430 can be avoided inthe regions corresponding to the second portion of the second insulationlayer 174 b.

Also in the etching step 430, the first insulation layer 172 on theupper surface of the connection electrode 160 may be selectively etchedtogether with the first portion of the second insulation layer 174 a onthe upper surface of the first IDT electrode 140 in a same single step.Accordingly, the thickness S of the first portion of the secondinsulation layer 174 a may be approximately equal to the thickness T ofthe first insulation layer 172. This may reduce an etching time of thefirst insulation layer 172 to form the extraction electrode 190 in step440 and therefore may achieve a simplified manufacturing process. Instep 450 the extraction electrode 190 is formed, and the externalterminal electrode 180 is also formed.

FIG. 6 is a block diagram schematically showing an example of anelectronic device 600 using an example of an acoustic wave element 610.The electronic device may be used in a cell phone or the like, forexample. As shown in FIG. 6, the electronic device 600 according to thisexample can include an acoustic wave element 610, a semiconductorelement 620 connected to the acoustic wave element 610, and areproduction device 630 connected to the semiconductor element 620. Theacoustic wave element 610 can include examples of the antenna duplexer100 and/or DMS filter 300 discussed above. The reproduction device 630can form a display unit such as a liquid crystal panel, a soundreproduction unit such as a speaker, or the like. Using the acousticwave element 610 according to the example of the present invention inthe electronic device 600 may provide a more highly-reliable electronicdevice 600 at lower cost.

The acoustic wave element 610 according to examples and embodimentsdisclosed herein may achieve the effect of improving mass-productioncapability of the acoustic wave element 610, and may be useful in avariety of electronic devices 600, such as a cell phone or other mobileor wireless communication device.

Further, embodiments of the acoustic wave element 610 may beincorporated into a module that may ultimately be used in a device, suchas a wireless communications device, for example, so as to provide amodule having enhanced performance. FIG. 7 is a block diagramillustrating one example of a module 700 including the acoustic waveelement 610. As discussed above, the acoustic wave element 610 caninclude examples of the antenna duplexer 100 and/or the DMS filter 300.The module 700 further includes connectivity 710 to provide signalinterconnections, packaging 720, such as for example, a packagesubstrate, for packaging of the circuitry, and other circuitry die 730,such as, for example amplifiers, pre-filters, modulators, demodulators,down converters, and the like, as would be known to one of skill in theart of semiconductor fabrication in view of the disclosure herein.

As discussed above, configuring an electronic device to use embodimentsof the acoustic wave element 610 can achieve the effect of realizing acommunication device, for example, having enhanced performance. FIG. 8is a schematic block diagram of one example of a communication device800 (e.g., a wireless or mobile device, such as a cell phone) that caninclude an embodiment of the antenna duplexer 100, optionally includingthe DMS filter 300 in either or both of the reception and transmissionfilters, as discussed above. The communication device 800 can representa multi-band and/or multi-mode device such as a multi-band/multi-modemobile phone, for example. In certain embodiments, the communicationdevice 800 can include the antenna duplexer 100, a transmission circuit810 connected to the antenna duplexer via the input terminal 186, areception circuit 820 connected to the antenna duplexer 600 via theoutput terminal 184, and an antenna 830 connected to the antennaduplexer via the antenna terminal 182. The transmission circuit 810 andreception circuit 820 may be part of a transceiver that can generate RFsignals for transmission via the antenna 830 and can receive incoming RFsignals from the antenna 830. As discussed above, in certainembodiments, the antenna duplexer 100 can be replaced with the module700 which includes the antenna duplexer. The communication device 800can further include a controller 840, a computer readable medium 850, atleast one processor 860, and a battery 870.

It will be understood that various functionalities associated with thetransmission and receiving of RF signals can be achieved by one or morecomponents that are represented in FIG. 8 as the transmission circuit810 and the reception circuit 820. For example, a single component canbe configured to provide both transmitting and receivingfunctionalities. In another example, transmitting and receivingfunctionalities can be provided by separate components. Similarly, itwill be understood that various antenna functionalities associated withthe transmission and receiving of RF signals can be achieved by one ormore components that are collectively represented in FIG. 8 as theantenna 830. For example, a single antenna can be configured to provideboth transmitting and receiving functionalities. In another example,transmitting and receiving functionalities can be provided by separateantennas. In yet another example in which the communication device is amulti-band device, different bands associated with the communicationdevice 800 can be provided with different antennas.

To facilitate switching between receive and transmit paths, the antennaduplexer 100 can be configured to electrically connect the antenna 830to a selected transmit or receive path. Thus, the antenna duplexer 100can provide a number of switching functionalities associated with anoperation of the communication device 800. In addition, as discussedabove, the antenna duplexer 100 includes the transmission filter 120 andreception filter 110, which are configured to provide filtering of theRF signals.

As shown in FIG. 8, in certain embodiments, a controller 840 can beprovided for controlling various functionalities associated withoperations of the antenna duplexer 100 and/or other operatingcomponent(s). In certain embodiments, the at least one processor 860 canbe configured to facilitate implementation of various processes foroperation of the communication device 800. The processes performed bythe at least one processor 860 may be implemented by computer programinstructions. These computer program instructions may be provided to theat least one processor 860, which can be a general purpose computer, aspecial purpose computer, or another programmable data processingapparatus to produce a machine, such that the instructions, whichexecute via the at least one processor of the computer or otherprogrammable data processing apparatus, create a mechanism for operatingthe communication device 800. In certain embodiments, these computerprogram instructions may also be stored in the computer-readable medium850. The battery 870 can be any suitable battery for use in thecommunication device 800, including, for example, a lithium-ion battery.

Having described above several aspects of at least one embodiment, it isto be appreciated various alterations, modifications, and improvementswill readily occur to those skilled in the art. Such alterations,modifications, and improvements are intended to be part of thisdisclosure and are intended to be within the scope of the invention.Accordingly, the foregoing description and drawings are by way ofexample only, and the scope of the invention should be determined fromproper construction of the appended claims, and their equivalents.

What is claimed is: 1-20. (canceled)
 21. A double-mode surface acousticwave filter comprising: an antenna terminal; a piezoelectric body; afirst interdigital transducer (IDT) electrode disposed on thepiezoelectric body; second and third IDT electrodes disposed on thepiezoelectric body opposing one another on either side of the first IDTelectrode along a propagation direction of a surface acoustic wave inthe double-mode surface acoustic wave filter; a connection electrodedisposed on the piezoelectric body and electrically connected to thefirst IDT electrode; an insulation disposed on surfaces of theconnection electrode, the first, second, and third IDT electrodes, andthe piezoelectric body, the insulation including a first portiondisposed on the surfaces of the first, second, and third IDT electrodesand having a first thickness in a direction perpendicular to the surfaceof the piezoelectric body; and a wiring electrode formed on theinsulation and insulated from the connection electrode by theinsulation, the insulation including a second portion disposed betweenthe connection electrode and the wiring electrode, the second portionhaving a second thickness in the direction perpendicular to the surfaceof the piezoelectric body, the second thickness being less than thefirst thickness.
 22. The double-mode surface acoustic wave filter ofclaim 21 further comprising first and second reflectors disposed on thepiezoelectric body and configured to reflect the surface acoustic wavein the propagation direction, the first reflector being disposedadjacent to the second IDT electrode such that the second IDT electrodeis positioned between the first IDT electrode and the first reflector inthe propagation direction, and the second reflector being disposedadjacent the third IDT electrode such that the third IDT electrode ispositioned between the first IDT electrode and the second reflectoralong the propagation direction.
 23. The double-mode surface acousticwave filter of claim 22 wherein the first IDT electrode includes a firstcomb-shaped electrode connected to the antenna terminal via theconnection electrode and a second comb-shaped electrode connected to aground electrode via the connection electrode, the first and secondcomb-shaped electrodes being arranged interdigitated with one another.24. The double-mode surface acoustic wave filter of claim 23 wherein thesecond IDT electrode includes third and fourth comb-shaped electrodesarranged interdigitated with one another, and the third IDT electrodeincludes fifth and sixth comb-shaped electrodes arranged interdigitatedwith one another, the third and fifth comb-shaped electrodes beingelectrically connected to one another via the connection electrode. 25.The double-mode surface acoustic wave filter of claim 24 wherein thefourth comb-shaped electrode is electrically connected to the sixthcomb-shaped electrode via the wiring electrode, and wherein the fourthand sixth comb-shaped electrodes are not electrically connected to thefirst comb-shaped electrode.
 26. The double-mode surface acoustic wavefilter of claim 22 wherein the piezoelectric body comprises a materialselected from a group consisting of lithium niobate, lithium tantalate,potassium niobate, and quartz.
 27. The double-mode surface acoustic wavefilter of claim 22 wherein the first, second, and third IDT electrodeseach comprises a material selected from a group consisting of aluminum,copper, gold, titanium, tungsten, molybdenum, platinum, and chromium.28. The double-mode surface acoustic wave filter of claim 27 wherein theconnection electrode comprises the material.
 29. An antenna duplexercomprising: a piezoelectric body; an antenna terminal, an inputterminal, and an output terminal; a first filter connected between theinput terminal and the antenna terminal; and a second filter connectedbetween the antenna terminal and the output terminal, the second filterbeing a double-mode surface acoustic wave filter including first,second, and third interdigital transducer (IDT) electrodes disposed onthe piezoelectric body and configured to excite a surface acoustic wave,the first IDT electrode being positioned between the second and thirdIDT electrodes in a propagation direction of the acoustic wave, thesecond filter further including a connection electrode, an insulation,and a wiring electrode insulated from the connection electrode by theinsulation, the connection electrode being disposed on a surface of thepiezoelectric body and electrically connected to the first IDTelectrode, the insulation including a first portion disposed on asurface of the connection electrode and having a first thickness abovethe connection electrode in a direction perpendicular to the surface ofthe piezoelectric body, the insulation further including a secondportion disposed between the connection electrode and the wiringelectrode, the second portion having a second thickness in the directionperpendicular to the surface of the piezoelectric body, the secondthickness being less than the first thickness.
 30. The antenna duplexerof claim 29 wherein the second filter further includes first and secondreflectors disposed on the piezoelectric body and configured to reflectthe surface acoustic wave in the propagation direction, the firstreflector being disposed adjacent to the second IDT electrode in thepropagation direction, and the second reflector being disposed adjacentthe third IDT electrode in the propagation direction.
 31. The antennaduplexer of claim 29 wherein the first IDT electrode includes a firstcomb-shaped electrode connected to the antenna terminal via theconnection electrode and a second comb-shaped electrode connected to aground electrode via the connection electrode, the first and secondcomb-shaped electrodes being arranged interdigitated with one another.32. The antenna duplexer of claim 31 wherein the second IDT electrodeincludes third and fourth comb-shaped electrodes arranged interdigitatedwith one another, and the third IDT electrode includes fifth and sixthcomb-shaped electrodes arranged interdigitated with one another, thethird and fifth comb-shaped electrodes being electrically connected toone another via the connection electrode.
 33. The antenna duplexer ofclaim 32 wherein the fourth comb-shaped electrode is electricallyconnected to the sixth comb-shaped electrode via the wiring electrode,and the fourth and sixth comb-shaped electrodes are not electricallyconnected to the first comb-shaped electrode.
 34. The antenna duplexerof claim 33 wherein the piezoelectric body comprises a material selectedfrom a group consisting of lithium niobate, lithium tantalate, potassiumniobate, and quartz.
 35. An antenna duplexer comprising: a piezoelectricbody; an antenna terminal, an input terminal, and an output terminal; afirst filter connected between the antenna terminal and the outputterminal; and a second filter connected between the input terminal andthe antenna terminal, the second filter being a double-mode surfaceacoustic wave filter including first, second, and third interdigitaltransducer (IDT) electrodes disposed on the piezoelectric body andconfigured to excite a surface acoustic wave, the first IDT electrodebeing positioned between the second and third IDT electrodes in apropagation direction of the acoustic wave, the second filter furtherincluding a connection electrode, an insulation, and a wiring electrodeinsulated from the connection electrode by the insulation, theconnection electrode being disposed on a surface of the piezoelectricbody and electrically connected to the first IDT electrode, theinsulation including a first portion disposed on a surface of theconnection electrode and having a first thickness above the connectionelectrode in a direction perpendicular to the surface of thepiezoelectric body, the insulation further including a second portiondisposed between the connection electrode and the wiring electrode, thesecond portion having a second thickness in the direction perpendicularto the surface of the piezoelectric body, the second thickness beingless than the first thickness.
 36. The antenna duplexer of claim 35wherein the second filter further includes first and second reflectorsdisposed on the piezoelectric body and configured to reflect the surfaceacoustic wave in the propagation direction, the first reflector beingdisposed adjacent to the second IDT electrode in the propagationdirection, and the second reflector being disposed adjacent the thirdIDT electrode in the propagation direction.
 37. The antenna duplexer ofclaim 35 wherein the first IDT electrode includes a first comb-shapedelectrode connected to the antenna terminal via the connection electrodeand a second comb-shaped electrode connected to a ground electrode viathe connection electrode, the first and second comb-shaped electrodesbeing arranged interdigitated with one another.
 38. The antenna duplexerof claim 37 wherein the second IDT electrode includes third and fourthcomb-shaped electrodes arranged interdigitated with one another, and thethird IDT electrode includes fifth and sixth comb-shaped electrodesarranged interdigitated with one another, the third and fifthcomb-shaped electrodes being electrically connected to one another viathe connection electrode.
 39. The antenna duplexer of claim 38 whereinthe fourth comb-shaped electrode is electrically connected to the sixthcomb-shaped electrode via the wiring electrode, and the fourth and sixthcomb-shaped electrodes are not electrically connected to the firstcomb-shaped electrode.
 40. The antenna duplexer of claim 35 wherein thepiezoelectric body comprises a material selected from a group consistingof lithium niobate, lithium tantalate, potassium niobate, and quartz.